This is a set of stereo view cards printed by Stereo Classics Studios in 1978. From what we can tell, they printed up a bunch of these and then went out of business. Even though they are so new, we've seen people selling these for $4 per card.
This set has slide numbers 1 through 13 of the "Woman's Lib" series. All cards are in very good condition. If the original card had information on the back, it is present. Otherwise they have the "Holmes Stereoscope" ad shown.